Measurement method of beam quality factor β for high energy laser

The measurement system of high energy laser beam quality factor β is mainly used for state debugging and comprehensive performance parameters diagnosis of laser system, while these parameters can evaluate the laser output performance and the far-field spot focusing ability of the laser system. Aiming at the defect that the beam quality factor β close to the diffraction limit occupying too few pixels in the area array detectors, a measurement method was proposed based on microscopic magnification with high-precision scanning slit, and the relevant scheme was analyzed and calculated. In addition, a verification scheme of measurement results using the combination of fixed aberration elements and collimator light sources was designed to analyze the uncertainty of measuring device of developed high energy laser beam quality factor β, and the measurement uncertainty was better than 10%.